Hybrid aerosol-generating element and method for manufacturing a hybrid aerosol-generating element

ABSTRACT

The hybrid aerosol-generating element for use in an aerosol-generating article comprises a liquid retention material for holding an aerosol-forming liquid and a solid aerosol-forming substrate arranged next to the liquid retention material.

The invention relates to a hybrid aerosol-generating element and amethod for manufacturing a hybrid aerosol-generating element. Inparticular the invention refers to an aerosol-generating element andarticle comprising a solid aerosol-forming substrate, in particular asolid aerosol-forming tobacco substrate, and an aerosol-forming liquid.

Electronic smoking systems that combine the use of e-liquids with theflavour of heated tobacco are known. However, there is the desire tohave a hybrid aerosol-generating element to be used in electronicdevices designed for the use of e-cigarettes. There is also the desireto have an efficient method for the manufacture of hybridaerosol-generating elements, in particular for hybrid aerosol-generatingelements used in rod-shaped aerosol-generating articles.

According to the invention, there is provided a hybridaerosol-generating element for use in an aerosol-generating article, forexample an e-cigarette. The hybrid aerosol-generating element comprisesa liquid retention material for holding an aerosol-forming liquid andcomprises a solid aerosol-forming substrate arranged next to the liquidretention material. Preferably, the solid aerosol-forming substrate is asolid aerosol-forming tobacco containing substrate.

In such a hybrid element a user not only gets the flavour or smokingexperience of the heated solid aerosol-forming substrate or only theflavour or smoking experience of the heated aerosol-forming liquid, butthe combination of the aerosol formed by heating the solidaerosol-forming substrate and the aerosol formed by evaporatedaerosol-forming liquid. In such a hybrid element, an aerosol-formingliquid contained in the liquid retention material may for examplecontinually flow or be drawn into the solid aerosol-forming substrate.By this, only the solid aerosol-forming substrate or regions of thesolid substrate must be heated, which may reduce energy required in anaerosol-generating system. Yet further, the provision of aerosol-formingliquid may significantly extend a consuming experience of anaerosol-generating element or of an aerosol-generating articlecomprising such an element. For example, a single tobacco substrate plugas used in aerosol-generating articles may provide aerosol for a coupleof puffs, such as for example 5 to 10 puffs. The provision of the liquidretention material with its capability of holding a certain amount ofaerosol-forming liquid may extend a consuming experience up to severaltenths of puffs, for example, to about 50 to 100 puffs.

While the solid aerosol-forming substrate is preferably provided fordelivering a tobacco flavour to an aerosol delivered to a user, theaerosol-forming liquid is preferably used to provide nicotine ornon-tobacco flavours to the aerosol generated in a corresponding deviceusing the hybrid aerosol-generating element.

The liquid retention material may hold a predetermined amount ofaerosol-forming liquid. The predetermined amount of liquid preferablycorresponds to predefined number of puffs to be available when using thehybrid aerosol-generating element.

The hybrid aerosol-generating element has a longitudinal axis and anextension of the element may be larger in the longitudinal directionthan in a direction perpendicular to the longitudinal direction. Thehybrid aerosol-generating element may for example be cylindrical orsubstantially cylindrical in shape. The aerosol-generating element maybe substantially elongate.

The aerosol-generating element may have a length between 8 and 14millimeter, for example 10 mm or 12 mm. The diameter of theaerosol-generating element may be between 5 millimeter and 12millimeter, for example about 8 millimeter.

In the hybrid aerosol-generating element, the liquid retention materialand the solid aerosol-forming substrate may be arranged next to eachother and subsequently along the longitudinal axis of the element.

Alternatively, the liquid retention material and the solidaerosol-forming substrate may be arranged at least partially at a samelongitudinal position of the hybrid aerosol-generating element. In suchembodiments the liquid retention material and the solid aerosol-formingsubstrate are arranged laterally next to each other at least partiallyover a length of the hybrid aerosol-generating element. The liquidretention material and the solid aerosol-forming substrate may bearranged at a same longitudinal position over an entire length of thehybrid aerosol-generating element. Preferably, the liquid retentionmaterial and the solid aerosol-forming substrate are arranged parallelto each other, preferably over the entire length of the element.

The liquid retention material may at least partially surround the solidaerosol-forming substrate. The liquid retention material may entirelysurround the solid aerosol-forming substrate in a longitudinaldirection. For example, the solid aerosol-forming substrate may be asolid cylindrically shaped aerosol-forming substrate arranged within atubular shaped liquid retention material.

The hybrid aerosol-generating element may comprise a liquid imperviouswrapper, wrapping the hybrid aerosol-generating element. The liquidimpervious wrapper may prevent a liquid in the liquid retention materialto seep out of the retention material in a direction other than thesolid aerosol-forming substrate, for example opposite the solidaerosol-forming substrate or out of the aerosol-generating element.

For aerosol generation, the hybrid aerosol-generating element may beheated by any kind of heating element suitable for and, for example,known from aerosol-generating systems. For example, the hybridaerosol-generating element may be used in inductively or resistivelyheated aerosol-generating systems or devices. Accordingly, anaerosol-generating device may be provided with one or more resistivelyheatable heating elements or with one or more inductively heatableheating elements. If used in inductively heated systems, the heatedportion of the heating element may be incorporated into the hybridaerosol-generating element. The hybrid aerosol-generating element maycomprise a susceptor material for inductively heating at least portionsof the element. The susceptor material may be arranged within the solidaerosol-forming substrate. The susceptor material may be introduced intothe solid aerosol-forming substrate before, during or aftermanufacturing the hybrid aerosol-generating element.

The liquid retention material is a high retention or high releasematerial (HRM) storing the liquid. Liquid retention material reduces therisk of spill, for example compared to cartridges or tank systems. Incase of failure or cracks of the housing of a tank or cartridge spilledliquid could lead to unintended contact with active electricalcomponents and biological tissue. The liquid retention material willintrinsically retain at least a portion of the liquid, which in turn isnot available for aerosolization before having left the retentionmaterial.

The liquid retention material may be substantially cylindrical in shape.The liquid retention material may have the form of a hollow cylinder.The liquid retention material may be substantially elongate. The liquidretention material may have a length and an (outer) diametercorresponding to the length and diameter of the hybridaerosol-generating element.

Aerosol-forming liquid to be stored in the retention material maycomprise at least one aerosol former and a liquid additive. Theaerosol-former may, for example, be propylene glycol or glycerol.

The aerosol-forming liquid may comprise water.

The liquid additive may be any one or a combination of a liquid flavouror liquid stimulating substance. Liquid flavour may for example comprisetobacco flavour, tobacco extract, fruit flavour or coffee flavour. Theliquid additive may, for example, be a sweet liquid such as for examplevanilla, caramel and cocoa, a herbal liquid, a spicy liquid, or astimulating liquid containing, for example, caffeine, taurine, nicotineor other stimulating agents known for use in the food industry.

The solid aerosol-forming substrate may comprise a tobacco-containingmaterial containing volatile tobacco flavour compounds, which arereleased from the substrate upon heating. Alternatively, theaerosol-forming substrate may comprise a non-tobacco material. Theaerosol-forming substrate may further comprise an aerosol former.Examples of suitable aerosol formers are glycerine and propylene glycol.

The aerosol-forming substrate may comprise, for example, one or more of:powder, granules, pellets, shreds, spaghetti strands, strips or sheetscontaining one or more of: herb leaf, tobacco leaf, fragments of tobaccoribs, reconstituted tobacco, homogenised tobacco, extruded tobacco andexpanded tobacco. The aerosol-forming substrate may be in loose form, ormay be provided in a suitable container or cartridge. For example, theaerosol-forming material of the aerosol-forming substrate may becontained within a paper or other outer wrapper and have the form of aplug.

Optionally, the aerosol-forming substrate may contain additional tobaccoor non-tobacco volatile flavour compounds, to be released upon heatingof the aerosol-forming substrate. The solid aerosol-forming substratemay also contain capsules that, for example, include the additionaltobacco or non-tobacco volatile flavour compounds and such capsules maymelt during heating of the solid aerosol-forming substrate.

The aerosol-forming substrate may comprise one or more sheets ofhomogenised tobacco material that has been gathered into a rod and cutto provide individual plugs of aerosol-forming substrate. Into this orthese gathered, rod-shaped sheets a susceptor material may be introducedbefore, during or after gathering the sheet into a rod. Preferably, theaerosol-forming substrate comprises a crimped and gathered sheet ofhomogenised tobacco material.

The solid aerosol-forming substrate may be substantially cylindrical inshape. The aerosol-forming substrate may be substantially elongate. Thesolid aerosol-forming substrate may have a length corresponding to thelength of the hybrid aerosol-generating element. The diameter of theaerosol-forming substrate may be between 3 millimeter and 7 millimeter,for example 5.6 mm.

Tobacco containing slurry and a tobacco sheet forming theaerosol-forming substrate made from the tobacco containing slurrycomprises tobacco particles, fiber particles, aerosol former, binder andfor example also flavours.

Preferably, the aerosol-forming tobacco substrate is a tobacco sheet,preferably crimped, comprising tobacco material, fibers, binder andaerosol former. Preferably, the tobacco sheet is a cast leaf. Cast leafis a form of reconstituted tobacco that is formed from a slurryincluding tobacco particles, fiber particles, aerosol former, binder andfor example also flavours.

Tobacco particles may be of the form of a tobacco dust having particlesin the order of 30 micrometers to 250 micrometers, preferably in theorder of 30 micrometers to 80 micrometers or 100 micrometers to 250micrometers, depending on a desired sheet thickness and casting gap,where the casting gap typically defines the thickness of the sheet.

Fiber particles may include tobacco stem materials, stalks or othertobacco plant material, and other cellulose-based fibers such as woodfibers having a low lignin content. Fiber particles may be selectedbased on the desire to produce a sufficient tensile strength for thesheet versus a low inclusion rate, for example, an inclusion ratebetween approximately 2 percent to 15 percent. Alternatively, fibers,such as vegetable fibers, may be used either with the above fiberparticles or in the alternative, including hemp and bamboo.

Aerosol formers included in the slurry for forming the cast leaf may bechosen based on one or more characteristics. Functionally, the aerosolformer provides a mechanism that allows it to be volatilized and conveynicotine or flavouring or both in an aerosol when heated above thespecific volatilization temperature of the aerosol former. Differentaerosol formers typically vaporize at different temperatures. An aerosolformer may be chosen based on its ability, for example, to remain stableat or around room temperature but able to volatize at a highertemperature, for example, between 40 degree Celsius and 450 degreeCelsius. The aerosol former may also have humectant type properties thathelp maintain a desirable level of moisture in an aerosol-formingsubstrate when the substrate is composed of a tobacco-based productincluding tobacco particles. In particular, some aerosol formers arehygroscopic material that function as a humectant, that is, a materialthat helps keep a substrate containing the humectant moist.

One or more aerosol former may be combined to take advantage of one ormore properties of the combined aerosol formers. For example, triacetinmay be combined with glycerol and water to take advantage of thetriacetin's ability to convey active components and the humectantproperties of the glycerol.

Aerosol formers may be selected from the polyols, glycol ethers, polyolester, esters, and fatty acids and may comprise one or more of thefollowing compounds: glycerol, erythritol, 1,3-butylene glycol,tetraethylene glycol, triethylene glycol, triethyl citrate, propylenecarbonate, ethyl laurate, triacetin, meso-Erythritol, a diacetinmixture, a diethyl suberate, triethyl citrate, benzyl benzoate, benzylphenyl acetate, ethyl vanillate, tributyrin, lauryl acetate, lauricacid, myristic acid, and propylene glycol.

The solid aerosol-forming substrate or the aerosol-forming slurryforming the substrate may contain waxes or fats, which waxes or fats areadded for a low temperature release of aerosol-forming substances fromthe solid aerosol-forming substrate. Some waxes and fats are known fortheir ability to lower the temperature where an aerosol former isreleased from a solid substrate containing said waxes or fats.

Preferably, tobacco containing slurry comprises homogenized tobaccomaterial and comprises glycerol or propylene glycol as aerosol former.Preferably, the aerosol-forming substrate is made of a tobaccocontaining slurry as described above.

Preferably, the solid aerosol-forming substrate has a capillary effectfor liquids. Preferably, the solid aerosol-forming substrate provides acapillary effect for aerosol-forming liquid retained in the liquidretention material. Preferably, the solid aerosol-forming substrateenables aerosol-forming liquid to be transported from the liquidretention material into the solid aerosol-forming substrate. The solidaerosol-forming substrate thus consists of or comprises capillarymaterial such that the aerosol-forming liquid is transferred by acapillary effect.

A capillary material is a material that actively conveys liquid from onepart of the material to another. The capillary material isadvantageously oriented in the solid aerosol-forming substrate to conveyaerosol-forming liquid into the solid aerosol-forming substrate.

The solid aerosol-forming substrate may have a fibrous structure or mayhave a spongy structure. The solid aerosol-forming substrate maycomprise a bundle of capillaries, a plurality of fibres, a plurality ofthreads, or may comprise fine bore tubes. The solid aerosol-formingsubstrate may comprise a combination of fibres, threads and fine-boretubes. The fibres, threads and fine-bore tubes may be generally alignedto convey liquid into the solid aerosol-forming substrate. The solidaerosol-forming substrate may comprise sponge-like material or maycomprise foam-like material. The structure of the solid aerosol-formingsubstrate may form a plurality of small bores or tubes, through whichthe liquid can be transported by capillary action. The capillary effectmay be such that liquid is transported to the location of a susceptor oranother heating element arranged in the solid aerosol-forming substrate,for example to a center of the substrate.

Susceptor material that may be used in the hybrid aerosol-generatingelement, in particular that may be incorporated into the solidaerosol-forming substrate may be a plurality of susceptor particles,such as susceptor granules or susceptor flakes.

The susceptor particles may be homogenously distributed in the hybridaerosol-generating element, preferably in the solid aerosol-formingsubstrate. The susceptor particles may also be localized in a specificregion of the hybrid aerosol-generating element, in particular in aspecific region of the solid aerosol-forming substrate.

The susceptor material may be an elongate susceptor arrangedlongitudinally in the hybrid aerosol-generating element, in particularwithin the solid aerosol-forming substrate. Preferably, such an elongatesusceptor is arranged radially centrally within the hybridaerosol-generating element, preferably radially centrally within thesolid aerosol-forming substrate.

An elongate susceptor has a length dimension that is greater than itswidth dimension or its thickness dimension, for example greater thantwice its width dimension or its thickness dimension. The elongatesusceptor is arranged substantially longitudinally within the element.This means that the length dimension of the elongate susceptor isarranged to be approximately parallel to the longitudinal direction ofthe element, for example within plus or minus 10 degrees of parallel tothe longitudinal direction of the element. In preferred embodiments,wherein the elongate susceptor is positioned in a radially centralposition within the element, it extends along the longitudinal axis ofthe hybrid aerosol-generating element.

The elongate susceptor is preferably in the form of a pin, rod, strip orblade. The elongate susceptor preferably has a length of between 5millimeter and 15 millimeter, for example, between 6 mm and 12 mm, orbetween 8 mm and 10 mm. A lateral extension of a susceptor material may,for example, be between 0.5 mm and 8 mm, preferably between 1 mm and 6mm, for example 4 millimeter. The elongate susceptor preferably has awidth of between 1 mm and 5 mm and may have a thickness of between 0.01mm and 2 mm, for example between 0.5 mm and 2 mm. In a preferredembodiment the elongate susceptor may have a thickness of between 10micrometer and 500 micrometer, or even more preferably between 10 and100 micrometer. If the elongate susceptor has a constant cross-section,for example a circular cross-section, it has a preferable width ordiameter of between 1 millimeter and 5 millimeter. If the elongatesusceptor has the form of a strip or blade, for example, if thesusceptor is made of a sheet-like susceptor material, the strip or bladepreferably has a rectangular shape having a width preferably between 2millimeter and 8 millimeter, more preferably, between 3 mm and 5 mm, forexample 4 mm, and a thickness preferably between 0.03 millimeter and0.15 millimeter, more preferably between 0.05 mm and 0.09 mm, forexample 0.07 mm.

Preferably, the elongate susceptor has a length which is the same orshorter than the length of the hybrid aerosol-generating element or ofthe solid aerosol-forming substrate. Preferably, the elongate susceptorhas a same length as the aerosol-generating element or as the solidaerosol-forming substrate.

As used herein, the term ‘susceptor’ refers to a material that canconvert electromagnetic energy into heat. When located within afluctuating electromagnetic field, typically eddy currents are inducedand hysteresis losses occur in the susceptor causing heating of thesusceptor. As the susceptor material is in direct physical and thermalcontact with the aerosol-forming substrate or the aerosol-forming liquidor both, the aerosol-forming substrate or liquid is heated by thesusceptor material.

The susceptor may be formed from any material that can be inductivelyheated to a temperature sufficient to generate an aerosol from the solidaerosol-forming substrate and the aerosol-forming liquid. Preferredsusceptors comprise a metal or carbon. A preferred susceptor maycomprise or consist of a ferromagnetic material, for example aferromagnetic alloy, ferritic iron, or a ferromagnetic steel orstainless steel. A suitable susceptor may be, or comprise, aluminium.Preferred susceptors may be formed from 400 series stainless steels, forexample grade 410, or grade 420, or grade 430 stainless steel. Differentmaterials will dissipate different amounts of energy when positionedwithin electromagnetic fields having similar values of frequency andfield strength. Thus, parameters of the susceptor such as material type,length, width, and thickness may all be altered to provide a desiredpower dissipation within a known electromagnetic field.

Preferred susceptors may be heated to a temperature in excess of 250degrees Celsius. Suitable susceptors may comprise a non-metallic corewith a metal layer disposed on the non-metallic core, for examplemetallic tracks formed on a surface of a ceramic core. A susceptor mayhave a protective external layer, for example a protective ceramic layeror protective glass layer encapsulating the susceptor. The susceptor maycomprise a protective coating formed by a glass, a ceramic, or an inertmetal, formed over a core of susceptor material.

The susceptor may be a multi-material susceptor and may comprise a firstsusceptor material and a second susceptor material. The first susceptormaterial is disposed in intimate physical contact with the secondsusceptor material. The first susceptor material is preferably usedprimarily to heat the susceptor when the susceptor is placed in afluctuating electromagnetic field. For example the first susceptormaterial may be aluminium, or may be a ferrous material such as astainless steel. The second susceptor material is preferably usedprimarily to indicate when the susceptor has reached a specifictemperature, that temperature possibly being the Curie temperature ofthe second susceptor material. The Curie temperature of the secondsusceptor material can be used to regulate the temperature of the entiresusceptor during operation. Thus, the Curie temperature of the secondsusceptor material should be below the ignition point of the solidaerosol-forming substrate. Suitable materials for the second susceptormaterial may include nickel and certain nickel alloys.

By providing a susceptor having at least a first and a second susceptormaterial, with either the second susceptor material having a Curietemperature and the first susceptor material not having a Curietemperature, or first and second susceptor materials having first andsecond Curie temperatures distinct from one another, the heating of theaerosol-forming substrate and temperature control of the heating may beseparated. It is preferable that the second susceptor material is amagnetic material selected to have a second Curie temperature that issubstantially the same as a desired maximum heating temperature. Thatis, it is preferable that the second Curie temperature is approximatelythe same as the temperature that the susceptor should be heated to inorder to generate an aerosol from the aerosol-forming substrate. Thesecond Curie temperature of the second susceptor material may, forexample, be selected such that, upon being heated by a susceptor that isat a temperature equal to the second Curie temperature, an overallaverage temperature of the aerosol-generating element does not exceed240° C.

Alternatively or in addition, for the control of a heating process ofthe hybrid aerosol-generating element, also the evaporation temperatureof the aerosol-forming liquid may be used as will be outlined in moredetail below.

According to the invention, there is also provided a hybridaerosol-generating article comprising a plurality of elements assembledin the form of a rod. The rod has a mouth end and a distal end upstreamfrom the mouth end. The plurality of elements comprises a hybridaerosol-generating element according to the invention and as describedherein. Advantages and features of the aerosol-generating articlerelating to the hybrid aerosol-generating element have been describedrelating to the hybrid aerosol-generating element and will not berepeated.

The plurality of elements may comprise at least one sealing elementarranged in an end-to-end relationship with the hybridaerosol-generating element. The at least one sealing element seals atleast a portion of the distal end of the hybrid aerosol-generatingelement. Preferably, the at least one sealing element seals that portionof the distal end of the aerosol-generating element that comprises theliquid retention material. By this, the at least one sealing elementprevents liquid to leave the liquid retention material in a longitudinalupstream direction of the aerosol-generating article.

The plurality of elements may comprise another sealing element, whereinthe other sealing element is arranged immediately downstream of thehybrid aerosol-generating element.

The other sealing element seals at least a portion of the proximal endof the hybrid aerosol-generating element. Preferably, the other sealingelement seals that portion of the proximal end of the aerosol-generatingelement that comprises the liquid retention material. By this, the othersealing element prevents liquid to leave the liquid retention materialin a longitudinal downstream direction of the aerosol-generatingarticle.

The plurality of elements may comprise two sealing elements, wherein onesealing element is arranged upstream of the hybrid aerosol-generatingelement and the second sealing element is arranged downstream of thehybrid aerosol-generating element. Preferably, the two sealing elementsare arranged directly adjacent the hybrid aerosol-generating element.

In some embodiments, the at least one sealing element may prevent asusceptor arranged in the aerosol-generating element to be displaced orto fall out of the aerosol-generating element upon transport or handlingof the article.

The at least one sealing element may be a hollow sealing element. Allsealing elements may be hollow sealing elements. A hollow sealingelement may seal a distal or also proximal end of a hollowtubular-shaped retention material and allows to pass air or in the caseof the downstream arranged sealing element, to pass aerosol through thesealing element. Preferably, sealing elements do not alter a resistanceto draw of the aerosol-generating article.

The sealing element may be made of any material suitable for use in anaerosol-generating article. The sealing element may, for example, bemade of a same material as used in a conventional mouthpiece filter, inan aerosol-cooling element or in a support element. Exemplary materialsare filter materials, ceramic, polymeric material, cellulose acetate,cardboard, non-inductively heatable metal, or zeolite.

Preferably, the sealing element is made of a heat resistant material.Heat resistant material for the sealing element is herein meant that thesealing element may resist temperatures of up to about 350 degreeCelsius. Advantageously, the sealing element is not affected by theheated aerosol-generating element or a potential heating elementarranged in the aerosol-generating element.

Preferably, the sealing element does not change its consistency,geometry or optics upon use of the article.

Preferably, the sealing element does not generate additional substancesto the generated aerosol during use of the article.

The sealing element has a (external) diameter that is approximatelyequal to a diameter of the aerosol-generating article. The sealingelement has a length that may be defined as the dimension along thelongitudinal axis of the aerosol-generating article. The length of thesealing element may be between 1 millimeter and 10 millimeter, forexample between 4 mm and 8 mm or between 5 mm and 7 mm. It is preferredthat the sealing element is substantially cylindrical. Preferably, asealing element is smaller than 8 mm. Preferably, the sealing elementhas a length of at least 2 millimeter in order to facilitate assembly ofan aerosol-generating article, preferably at least 3 millimeter or atleast millimeter.

The minimum sizes of the length of the sealing element facilitate orallow use of conventional combiners to assemble the plurality ofelements to a rod shape.

As a general rule, whenever a value is mentioned throughout thisapplication, this is to be understood such that the value is explicitlydisclosed. However, a value is also to be understood as not having to beexactly the particular value due to technical considerations.

The plurality of elements may for example also comprise one or severalof the following elements: a mouthpiece element, a support element, oran aerosol-cooling element.

The mouthpiece element may be located at the mouth end or downstream endof the aerosol-generating article.

The mouthpiece element may comprise at least one filter segment. Thefilter segment may be a cellulose acetate filter plug made of celluloseacetate tow. A filter segment may have low particulate filtrationefficiency or very low particulate filtration efficiency. A filtersegment may be longitudinally spaced apart from the hybridaerosol-generating element. The filter segment may have a length between5 millimeter and 14 millimeter, for example 7 millimeter.

A user contacts the mouthpiece element in order to pass an aerosolgenerated by the aerosol-generating article through the mouthpieceelement to the user. Thus, a mouthpiece element is arranged downstreamof a hybrid aerosol-generating element.

The mouthpiece element preferably has an external diameter that isapproximately equal to the external diameter of the aerosol-generatingarticle. The mouthpiece element may have a length of between 5millimeter and 25 millimeter, preferably a length of between 10 mm and17 mm. In a preferred embodiment, the mouthpiece element has a length of12 mm or 14 mm. In another preferred embodiment, the mouthpiece elementhas a length of 7 mm.

A support element may be located immediately downstream of the hybridaerosol-generating element and may abut the hybrid aerosol-generatingelement.

The support element may be formed from any suitable material orcombination of materials. For example, the support element may be formedfrom one or more materials selected from the group consisting of:cellulose acetate; cardboard; crimped paper, such as crimped heatresistant paper or crimped parchment paper; and polymeric materials,such as low density polyethylene (LDPE). In a preferred embodiment, thesupport element is formed from cellulose acetate.

The support element may comprise a hollow tubular element. In apreferred embodiment, the support element comprises a hollow celluloseacetate tube. A sealing element sealing a proximal end of the hybridaerosol-generating element may be a support element or a support elementmay be designed as a sealing element, respectively.

The support element preferably has an external diameter that isapproximately equal to the external diameter of the aerosol-generatingarticle.

The support element may have a length of between 5 mm and 15 mm. In apreferred embodiment, the support element has a length of 8 mm.

An aerosol-cooling element may be located downstream of the hybridaerosol-generating element, for example immediately downstream of asupport element or a sealing element, and may abut the support elementor the sealing element.

As used herein, the term ‘aerosol-cooling element’ is used to describean element having a large surface area and a low resistance to draw. Inuse, an aerosol formed by volatile compounds released from theaerosol-forming substrate is drawn through the aerosol-cooling elementbefore being transported to the mouth end of the aerosol-generatingarticle. In contrast to high resistance-to-draw filters, for examplefilters formed from bundles of fibers, aerosol-cooling elements have alow resistance to draw. Chambers and cavities within anaerosol-generating article such as expansion chambers and supportelements are also not considered to be aerosol cooling elements.

An aerosol-cooling element preferably has a porosity in a longitudinaldirection of greater than 50 percent. The airflow path through theaerosol-cooling element is preferably relatively uninhibited. Anaerosol-cooling element may be a gathered sheet or a crimped andgathered sheet. An aerosol-cooling element may comprise a sheet materialselected from the group consisting of polyethylene (PE), polypropylene(PP), polyvinylchloride (PVC), polyethylene terephthalate (PET),polylactic acid (PLA), cellulose acetate (CA), and aluminium foil or anycombination thereof.

In a preferred embodiment, the aerosol-cooling element comprises agathered sheet of biodegradable material. For example, a gathered sheetof non-porous paper or a gathered sheet of biodegradable polymericmaterial, such as polylactic acid or a grade of Mater-Bi<®> (acommercially available family of starch based copolyesters).

An aerosol-cooling element preferably comprises a sheet of PLA, morepreferably a crimped, gathered sheet of PLA. An aerosol-cooling elementmay be formed from a sheet having a thickness of between 10 micrometerand 250 micrometer, for example 50 micrometer. An aerosol-coolingelement may be formed from a gathered sheet having a width of between150 millimeter and 250 millimeter. An aerosol-cooling element may have aspecific surface area of between 300 millimeter² per millimeter lengthand 1000 millimeter² per millimeter length between 10 millimeter² per mgweight and 100 millimeter² per mg weight. In some embodiments, theaerosol-cooling element may be formed from a gathered sheet of materialhaving a specific surface area of about millimeter² per mg weight. Anaerosol-cooling element may have an external diameter of between 5millimeter and millimeter, for example 7 mm.

The length of the aerosol-cooling element may be between millimeter and15 millimeter, for example 13 millimeter or may in alternativeembodiments be between 15 millimeter and millimeter, preferably between16 millimeter and millimeter, for example 18 millimeter.

The length of the aerosol-cooling element may even be shorter accordingto a desired or required cooling effect. For example, waxes or fats fora low temperature release of aerosol-forming substances from the solidaerosol-forming substrate may be contained in the solid substrate. Insuch embodiments, an aerosol-cooling element may be shortened to a fewmillimeter, for example 5 to 10 millimeter, or may possibly be omitted.

The plurality of elements of the aerosol-forming article may becircumscribed by an outer wrapper. The outer wrapper may be formed fromany suitable material or combination of materials. Preferably, the outerwrapper is a cigarette paper.

According to the invention, there is also provided an aerosol-generatingsystem comprising a hybrid aerosol-generating article according to theinvention and as described herein. The system further comprises aheating element for heating at least a portion of the hybridaerosol-generating element of the hybrid aerosol-generating article, apower source to provide energy to the heating element and a controlelectronics configured to control a heating of the hybridaerosol-generating element.

The control electronics may be programmed to determine a temperature ofthe at least a portion of the hybrid aerosol-generating element, whichtemperature is used to control the heating of the at least a portion ofthe hybrid aerosol-generating element.

With resistive heating elements, an ohmic resistance of the heatingelement may be correlated to the temperature of the heating element. Ininductively heated systems, a temperature of a susceptor may bedetermined from an apparent ohmic resistance (Ra) of an inductive“heating circuit”. Such an inductive heating circuit and determinationof apparent resistance and their correlation with a temperature of thesusceptor is described in detail in the international patent publicationWO2015/177256.

In the aerosol-generating system, an evaporation temperature of anaerosol-forming liquid provided in the liquid retention material of theaerosol-generating element may be used to control the heating of thehybrid aerosol-generating element or, for example, of the solidaerosol-forming substrate of the element. The evaporation temperature ofthe aerosol-forming liquid may correspond to a predefined maximumheating temperature.

The aerosol-forming liquid may be heated up to its evaporationtemperature, where the liquid is evaporated. As long as aerosol-formingliquid is present, for example in the solid aerosol-generatingsubstrate, said substrate may not be heated above the evaporationtemperature of the liquid before all the liquid has been evaporated. Aslong as liquid may seep into the solid substrate, the solid substratewill not be heated above the evaporation temperature thus theevaporation temperature corresponding to a maximum heating temperature.

The aerosol-generating system may comprise an aerosol-generating devicecomprising a device housing and a cavity arranged in the device housing.The cavity has an internal surface shaped to accommodate at least aportion of the hybrid aerosol-generating article. The cavity is arrangedsuch that upon accommodation of the at least a portion of the hybridaerosol-generating article in the cavity the heating element is arrangedsuch that the at least a portion of the hybrid aerosol-generatingelement is heated during operation of the device.

Preferably, the entire aerosol-generating element of the article isaccommodated in the cavity.

In a resistively heated device, a heating element is typically insertedinto the aerosol-generating article, or into the aerosol-generatingelement, respectively.

In an inductively heated device, the cavity is arranged such that uponaccommodation of at least the portion of the aerosol-generating elementin the cavity an inductor comprised in the device may be inductivelycoupled to a susceptor arranged in thermal contact with the hybridaerosol-generating element, for example to a susceptor arranged in theaerosol-generating element, preferably, in the solid aerosol-formingsubstrate.

According to the invention, there is also provided a method formanufacturing hybrid aerosol-generating elements for use in anaerosol-generating article. The method comprises the steps of providinga continuous solid aerosol-forming substrate and a continuous liquidretention material and guiding the continuous liquid retention materialparallel to the continuous solid aerosol-forming substrate. Yet furthersteps comprise forming the continuous solid aerosol-forming substrateand the continuous liquid retention material into a continuous rod andcutting the continuous rod into individual hybrid aerosol-generatingelements.

The continuous retention material may thereby be arranged along onelongitudinal side, for example a first half, of the continuous rod andthe continuous solid aerosol-forming substrate may be arranged along theother longitudinal side, for example other half, of the continuous rod.

The continuous retention material may also be arranged to at leastpartially or entirely surround the continuous solid aerosol-formingsubstrate. In these embodiments, the method preferably comprises thefurther steps of forming the solid continuous aerosol-forming substrateat least partially into a continuous rod, then arranging the continuousliquid retention material around the at least partially formedcontinuous rod of solid aerosol-forming substrate, and then forming thecontinuous liquid retention material arranged around the at leastpartially formed continuous rod of aerosol-forming substrate into acontinuous rod. By this, a continuous rod may be formed having an outershell of retention material and a core of solid aerosol-formingsubstrate.

The method may further comprise the step of wrapping the continuous rodwith a fluid impervious wrapper before cutting the continuous rod.

A liquid may be present in the continuous retention material beforeforming a continuous rod or may be provided to the retention materialafter forming the continuous rod. However, the liquid is provided to theliquid retention material before wrapping the continuous rod with theliquid impervious wrapper.

For manufacturing a hybrid aerosol-generating element for inductiveheating applications a susceptor may be incorporated into the elementupon manufacturing the element. In these embodiments, the method mayfurther comprise the step of introducing a susceptor material,preferably a continuous susceptor material, into the solid continuousaerosol-forming substrate. Preferably, the susceptor material, forexample a band or filament is inserted into the element, preferably intothe continuous solid aerosol-forming substrate before forming a rod.Preferably, the susceptor is incorporated into a partially formedcontinuous rod of solid aerosol-forming substrate.

Preferably, the solid continuous aerosol-forming substrate is providedin the form of a sheet-like continuous substrate.

Preferably, the continuous liquid retention material is provided in theform of a sheet-like continuous web, preferably a porous web.

Hybrid aerosol-generating elements cut from the continuous rod may thenbe assembled with further elements in an end-to-end position forming arod. The assembled elements may then be wrapped with an outer wrapper tofrom the hybrid aerosol-generating article.

The invention is further described with regard to embodiments, which areillustrated by means of the following drawings, wherein:

FIG. 1 is a schematic illustration of a hybrid aerosol-generatingarticle;

FIG. 2 is a schematic illustration of a manufacturing method of hybridaerosol-generating elements and articles comprising a susceptor.

FIG. 1 illustrates an aerosol-generating article. The aerosol-generatingarticle comprises five elements arranged in coaxial alignment: a firstsealing element 1, a hybrid aerosol-forming element 2, a second sealingelement 3 also acting as support element, an aerosol-cooling element 4,and a mouthpiece 5. Each of these five elements is a substantiallycylindrical element, each having substantially the same diameter. Thefive elements are arranged sequentially and are circumscribed by anouter wrapper (not shown) to form a cylindrical rod.

The first sealing element 1 is located at the extreme distal or upstreamend 80 of the aerosol-generating article. The first sealing element 1 isshown as a hollow tube, for example a hollow cellulose acetate tube. Thehollow tube allows air to pass through the first sealing element 1 andinto the hybrid aerosol-forming element 2 arranged adjacent anddownstream of the first sealing element 1. The hollow tube of the firstsealing element 1 has an inner diameter, which is smaller than the innerdiameter of a liquid retention material tube 22 of the hybridaerosol-generating substrate element 2. The material of the firstsealing element is impervious to a liquid held in the liquid retentionmaterial tube 22. Thus, the first sealing element 1 prevents liquid toleave the distal end of the retention material tube 22 in an upstreamdirection.

The hybrid aerosol-generating element 2 comprises a tobacco plug 21 of asolid aerosol-forming substrate material comprising a gathered sheet ofcrimped homogenised tobacco material. The crimped sheet of homogenisedtobacco material comprises glycerol or propylene glycol asaerosol-former. The tobacco plug 21 may have a diameter of about 5.6 mm.

A susceptor blade 23 is located along a radially central axis of theaerosol-forming element 2. The susceptor has about a same length thanthe length of the aerosol-forming element 2. The susceptor may be aferritic iron material having a length of 10 mm to 12 mm, a width of 3mm and a thickness of 1 mm.

A diameter of the susceptor blade 23 is larger than the inner diameterof the first sealing element 1. Thus, the susceptor blade 23 isprevented from dislodging or falling out of the aerosol-generatingelement 2 by the first sealing element 1.

The liquid retention material tube 22 is arranged around the tobaccoplug 21. The liquid retention material is a porous material, for examplea plastics material and adapted to retain an amount of aerosol-formingliquid. The aerosol-forming liquid comprises glycerol or propyleneglycol as aerosol-former and nicotine. The thickness of the tube wall ofthe liquid retention material tube is about 0.8 mm.

The hybrid aerosol-forming element 2 is wrapped by an impervious wrapper24. The wrapper 24 is impervious to the aerosol-forming liquid in theretention material 22.

The second sealing element 3 or support element is located immediatelydownstream of the aerosol-forming element 2 and abuts theaerosol-forming element 2. In FIG. 1 , the second sealing element 3 isidentical to the first sealing element 1. The second sealing element isshown as a hollow tube, for example a hollow cellulose acetate tube.

The second sealing element 3 locates the aerosol-forming element 2 inthe aerosol-generating article.

The second sealing element 3 allows evaporated substances from oraerosol formed in the hybrid aerosol-forming element 2 to pass throughthe second sealing element 3 and further downstream into theaerosol-cooling element 4 arranged adjacent and downstream of the secondsealing element 3. The hollow tube of the second sealing element 3 hasan inner diameter, which is smaller than the inner diameter of theliquid retention material tube 22 of the hybrid aerosol-generatingelement 2. The material of the second sealing element 3 is impervious tothe liquid held in the liquid retention material tube 22. Thus, thesecond sealing element 3 prevents liquid to leave the proximal end ofthe retention material tube 22 in a downstream direction.

Thus, liquid in the retention material 22 may leave the retentionmaterial only into the direction of the tobacco plug 21. If the same isheated by the susceptor 23, aerosol-forming substances in the tobaccoplug 21 are evaporated and aerosol-forming liquid is drawn from theretention material into the tobacco plug 21.

The second sealing element 3 also acts as a spacer to space theaerosol-cooling element 4 from the aerosol-forming element 2.

The aerosol-cooling element 4 is located immediately downstream of thesecond sealing element 3 and abuts the second sealing element 3. In use,volatile substances released from the aerosol-forming element 2 passalong the aerosol-cooling element 4 towards the mouth end 81 of theaerosol-generating article. The volatile substances may cool within theaerosol-cooling element 4 to form an aerosol that is inhaled by theuser. The aerosol-cooling element comprises a crimped and gathered sheetof polylactic acid circumscribed by a wrapper (not shown). The crimpedand gathered sheet of polylactic acid defines a plurality oflongitudinal channels that extend along the length of theaerosol-cooling element 4.

The mouthpiece 5 is located immediately downstream of theaerosol-cooling element 4 and abuts the aerosol-cooling element 4. InFIG. 1 , the mouthpiece 5 comprises a conventional cellulose acetate towfilter of low filtration efficiency.

To assemble the aerosol-generating article, the five cylindricalelements described above are aligned and tightly wrapped within an outerwrapper. The outer wrapper may be a conventional cigarette paper.

The aerosol-generating article has a proximal or mouth end 81, which auser inserts into his or her mouth during use, and a distal end 80located at the opposite end of the aerosol-generating article to themouth end 81. Once assembled, the total length of the aerosol-generatingarticle is about 45 mm to 53 mm and the diameter is about 7.2 mm.

In use air is drawn through the aerosol-generating article as indicatedby arrow 7 by a user from the distal end 80 to the mouth end 81. Thedistal end 80 of the aerosol-generating article may also be described asthe upstream end of the aerosol-generating article and the mouth end 81of the aerosol-generating article may also be described as thedownstream end of the aerosol-generating article.

Upon manufacturing the article, the five elements are prepared,assembled and wrapped by the outer wrapper.

The susceptor 23 may be inserted into the tobacco plug 21 prior to theassembly of the plurality of elements to form a rod. Alternatively, allelements except for the first sealing element 1 may be assembled. Thesusceptor may then be inserted into the distal end of the assembly suchthat it penetrates the tobacco plug 21.

The aerosol-generating article of FIG. 1 is designed to engage with anelectrically-operated aerosol-generating device preferably comprising aninduction coil, or inductor, in order to be smoked or consumed by auser.

In FIG. 2 an embodiment of a manufacturing method for hybridaerosol-generating substrate elements and articles comprising suchelements is illustrated.

Continuous tobacco material 25, for example a sheet of cast leaf isprovided on a reel 44. The tobacco sheet 25 is crimped between crimpingrollers 60.

Continuous susceptor material 54, for example a susceptor band material,is provided on another reel. The crimped tobacco sheet and the susceptorband 54 are led together into a garniture tongue 61, where a continuousrod is formed comprising the tobacco material enveloping the susceptorband.

The continuous tobacco rod is enveloped by a high retention material 64,for example a web of retention material, which is provided on a furtherreel. The retention material 64 may contain liquid before being wrappedaround the tobacco rod. Liquid may also be provided to the retentionmaterial after being wrapped around the tobacco rod.

The continuous rod is additionally provided with a liquid imperviouswrapper, which may be provided on yet another reel (not shown). Thefinal continuous rod 9 is cut with a cutter 62 into rod segments 90 ordirectly into final-length aerosol-generating substrate elements 2. Across-section 20 through a rod segment 90 or through theaerosol-generating substrate elements 2 is also shown in FIG. 2 .

After the continuous rod 9 or the rod segments 90 have been cut intoaerosol-generating substrate elements 2, the elements 2 may be providedto an article assembling machine.

Elements of the article are aligned in a row on the outer wrapper 74together with an aerosol-generating substrate element 2. The elements orsegments are then assembled and wrapped with the outer wrapper 74forming a hybrid aerosol-generating article adapted for beinginductively heated.

In the embodiments shown in the figures, susceptor material is describedor shown to be arranged within the solid aerosol-forming substrate ortobacco plug, heating the tobacco plug and the liquid that has seepedinto the plug. Thereby heating may mainly be limited to the tobaccoplug, while the aerosol-forming liquid in the retention material is notor not significantly heated. However, susceptor material mayalternatively or additionally be provided in, for example incorporatedinto, the liquid retention material. By heating the liquid in theretention material, increased delivery of aerosol-forming liquid may beachieved.

1-13. (canceled)
 14. A hybrid aerosol-generating element for use in anaerosol-generating article, the hybrid aerosol-generating elementcomprising: a liquid retention material holding an aerosol-formingliquid in the form of glycerin, and a tobacco containing solidaerosol-forming substrate, wherein the tobacco containing solidaerosol-forming substrate is arranged next to the liquid retentionmaterial.
 15. The hybrid aerosol-generating element according to claim14, wherein the tobacco containing solid aerosol-forming substratecomprises homogenized tobacco.
 16. The hybrid aerosol-generating elementaccording to claim 14, further comprising a liquid impervious wrapperwrapping the hybrid aerosol-generating element.
 17. The hybridaerosol-generating element according to claim 14, having a diameterbetween 5 millimeters and 12 millimeters.
 18. The hybridaerosol-generating element according to claim 14, wherein the liquidretention material is a sheet.
 19. The hybrid aerosol-generating elementaccording to claim 14, wherein the tobacco containing solidaerosol-forming substrate comprises a capillary material in contact withthe liquid retention material.
 20. The hybrid aerosol-generating elementaccording to claim 19, wherein the capillary material enables glycerineto be transported into the tobacco containing solid aerosol-formingsubstrate.
 21. The hybrid aerosol-generating element according to claim14, wherein the liquid retention material and the tobacco containingsolid aerosol-forming substrate are arranged subsequently along thelongitudinal axis of the hybrid aerosol-generating element.
 22. Thehybrid aerosol-generating element according to claim 14, wherein theliquid retention material and the tobacco containing solidaerosol-forming substrate are arranged at least partially at a samelongitudinal position of the hybrid aerosol-generating element.
 23. Thehybrid aerosol-generating element according to claim 22, wherein theliquid retention material and the tobacco containing solidaerosol-forming substrate are arranged at a same longitudinal positionover an entire length of the hybrid aerosol-generating element.
 24. Thehybrid aerosol-generating element according to claim 14, having a lengthbetween 8 millimeters and 14 millimeters.
 25. The hybridaerosol-generating element according to claim 1, wherein the tobaccocontaining solid aerosol-forming substrate comprises granules.
 26. Thehybrid aerosol-generating element according to claim 14, wherein thetobacco containing solid aerosol-forming substrate is contained withinpaper.
 27. A hybrid aerosol-generating article comprising a plurality ofelements assembled in the form of a rod, the plurality of elementscomprising the hybrid aerosol-generating element according to claim 14.28. The hybrid aerosol-generating article according to claim 27, whereinthe plurality of elements comprises at least one of a mouthpieceelement, a support element, a sealing element or an aerosol-coolingelement.
 29. The hybrid aerosol-generating article according to claim28, wherein the mouthpiece element is located at a mouth end of theaerosol-generating article, the mouthpiece element comprising at leastone filter segment.
 30. The hybrid aerosol-generating article accordingto claim 29, wherein the filter segment is longitudinally spaced apartfrom the hybrid aerosol-generating element.
 31. The hybridaerosol-generating article according to claim 27, wherein the pluralityof elements comprises a support element being a hollow element arrangeddownstream of the hybrid aerosol-generating element.
 32. The hybridaerosol-generating article according to claim 31, wherein the supportelement comprises cellulose acetate.
 33. The hybrid aerosol-generatingarticle according to claim 29, wherein the plurality of elementscomprises at least one sealing element arranged in an end-to-endrelationship with the hybrid aerosol-generating element, the at leastone sealing element sealing at least a portion of a distal end of thehybrid aerosol-generating element.